1. Field of the Invention
This invention relates to electrical components, such as transformers, chokes and, more particularly, to a method and system for forming particulate or powder-like materials into a unitary, firmly-compacted body of material to provide transformers, chokes, commutators, rotors and/or stators for motors.
2. Description of Related Art
Powder metal bodies have been formed by means of pressure and heat. Such a method has also been used for forming unitary bodies from other particulate materials. U.S. Pat. Nos. 5,405,574; 5,611,139; 5,611,230 and 5,689,797 all disclose systems and methods for compacting powder-like materials. For example, U.S. Pat. No. 5,689,797 discloses a method for producing an annular body wherein a container is filled with a particulate material and an electrically conductive drive member is used to induce a current in the container to cause a compaction pressure to be applied to the particulate material. This causes the material to compress and compact within the container into an annular body of magnetic compacted particulate material.
Similarly, U.S. Pat. No. 5,611,139 discloses a structure for increasing the density of a powder comprising a support for receiving the powder and an electrically conductive driver positioned adjacent the support and a connector for connecting the driver to a source of electrical energy for energizing the driver to create a magnetic field to pressure the powder, thereby producing an integral part from the powder. These patents are owned by the same Assignee as the present invention, and are incorporated herein by reference and made a part hereof.
FIG. 11 shows a prior art magnetic compaction system having a direct current power supply A to which is connected electrical conductors B and C. Connected to the conductor B is a switch D which is also connected to a conductor E. The conductor E and the conductor C have joined there between a capacitor. The conductor E is also connected to a switch G which is also connected a connector H. The conductor C and the conductor H are connected to a solenoid I which encompasses an electrically conductive container I.
In operation, the switch is closed, and the capacitor F is charged from the power supply A. After the capacitor F is completely charged, the switch D is opened and the switch G is closed. When the switch G is closed, a large quantity of electrical current flows from the capacitor F through the solenoid or energizing coil I. When the electrical current flows through the solenoid or energizing coil I, magnetic pressure is applied upon the electrical conductive container J. This pressure acts inwardly upon the electrically conductive container J, and the transverse dimensions of the electrically conductive J are reduced. Thus, compaction occurs within the electrically conductive container 38 and the powder-like material K is compressed and compacted to form a dense body. Thus, the powderous material K within the electrically conductive container J becomes a dense body.
Due to the fact that the solenoid or energizing coil I tends to expand radially as current flows there through, suitable means have been employed to restrain the coil I against lateral expansion as current flows there through. For example, as shown in FIG. 11, a wall L may closely encompass the energizing solenoid or coil I and restrain the solenoid or coil I against expansion as current flows there through.
One problem with the current designs and configurations of ferrite-based transformers is that they tend to be relatively large. Consequently, the costs associated with manufacturing and producing such transformers tends to be relatively high, and reliability is not as good as desired.
What is needed, therefore, is a transformer design and manufacturing process capable of utilizing dynamic magnetic compaction technology which facilitates reducing the size of the parts, such as the transformers, and which reduces or eliminates the number of manufacturing and assembly steps required by prior art techniques.
This invention provides a system and method wherein powder-like and/or particulate materials are received in a container along with a insulated coil and subject to dynamic magnetic compaction to produce a transformer, choke, rotor or stator for an electric motor and the like.
The method and related structure of this invention applies pressures generated by non-contact electromagnetic forces. These electromagnetic pressures are generated by employing suitably shaped energizing coils, such as solenoids or the like, which have the necessary capacity. An electrically conductive container is provided wherein a powder-like material and an inner coil is situated therein. An electrical current is passed through a solenoid or energizing coil surrounding the container, and the electrically conductive container is reduced in transversed dimensions, thereby encasing both the particulate material and inner coil to provide a high density body which may be used as a transformer or choke. The compaction of the particulate material is preferably performed by electromagnetic compaction as electrical energy is applied in short time pulses.
An object of this invention is to provide a compacted electrical component having improved manufacturing characteristics, reduced cost and improved reliability.
Another object of this invention is to provide an electrical component manufactured using dynamic magnetic compaction.
In one aspect, this invention comprises a component part comprising a conductive container for receiving a powderous material, an internal coil having an insulating coating situated in the conductive container, the conductive container compacting the powderous material about the internal coil to form the component part when the conductive container is subject to an electromagnetic field.
In another aspect, this invention comprises a method of making a component part comprising the steps of providing a conductive container for receiving a powderous material, situating an internal coil having an insulating coating situated in the conductive container, situating a powderous material in the conductive container, energizing the conductive container to magnetically compact the conductive container and the powderous material to provide the component part.
In still another aspect, this invention comprises a compaction system comprising a power supply, a plurality of conductors coupled to the power supply, an energizing coil for providing an electromagnetic field, at least one capacitor connected across the energizing coil, at least one switch coupled to the plurality of conductors and selectively coupling the power supply to at least one capacitor and at least one switch, the energizing coil be situated relative to a conductive container in order to generate an electromagnetic field to energize a conductive container to magnetically compact a powderous material about an internal coil to form a component part, wherein the internal coil comprises an insulating coating.
Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings.